With an increasingly higher requirement for energy density of a portable electronic device and an electric automobile, a research and development of a high-performance lithium-ion secondary battery become increasingly important.
With a relatively high theoretical capacity (up to 4200 mAh/g) and a good intercalation/deintercalation capability, a pure silicon material becomes a most promising new-type cathode material for efficient lithium-ion storage. However, a volume of the silicon material changes by more than 300% during a lithium deintercalating and intercalating process, causing the silicon material to extremely easily fall from a current collector; in addition, the silicon material has a relatively low conductivity. Currently, the industry modifies the silicon material mainly by adopting four manners: nanocrystallizing, filming, compounding, and designing a special multi-level structure. However, effects are unsatisfactory, either because a preparation process is so complex that it is difficult to implement commercialization, or because the introduction of a large quantity of inactive substances greatly reduces the advantage of a high capacity of the pure silicon material.